FormalConjectures/Books/BugeaudDistributionModuloOne/IntDistanceDistribution.lean

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5 declarations, 4 contain sorry, 0 declared as axioms

Bugeaud Collection of Conjectures and Open Questions: Fractional Parts of Powers

Chapter 10 of the book collects open questions. This file formalizes Problems 10.1, 10.2, 10.3 and the unnumbered conjecture by Waldschmidt.

References:

Imports (1)
  1. theorem Bugeaud01.problem_10_1 Problem 10.1 sorry line 52 source

    Source documentation

    Problem 10.1. Are there a transcendental number $\alpha$ and a positive real number $\xi$ such that $\lVert \xi \alpha^n \rVert$ tends to~$0$ as~$n$ tends to infinity? [Har19] (Trivial for $|\alpha| < 1$)

    depends on sorry what this means

    Statement uses: Iff, True, Exists, Real, And, LT.lt, OfNat.ofNat, abs, Transcendental, Rat, Filter.Tendsto, Nat, distToNearestInt, HMul.hMul, HPow.hPow, Filter.atTop, nhds

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    57 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem problem_10_1 : answer(sorry) ↔
        ∃ (α ξ : ℝ), 1 < |α| ∧ Transcendental ℚ α ∧ 0 < ξ ∧
          Filter.Tendsto (fun n : ℕ ↦ distToNearestInt (ξ * α ^ n)) Filter.atTop (nhds 0) := by
    …

    Mentions: distToNearestInt

  2. theorem Bugeaud01.problem_10_2 Problem 10.2 sorry line 62 source

    Source documentation

    Problem 10.2. To prove that $\lVert e^n \rVert$ does not tend to 0 as n tends to infinity.

    depends on sorry what this means

    Statement uses: Not, Filter.Tendsto, Nat, Real, distToNearestInt, Real.exp, Filter.atTop, nhds, OfNat.ofNat

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    17 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem problem_10_2 :
        ¬ Filter.Tendsto (fun n : ℕ ↦ distToNearestInt (Real.exp n)) Filter.atTop (nhds 0) := by
    …

    Mentions: distToNearestInt

  3. theorem Bugeaud01.problem_10_3 Problem 10.3 sorry line 71 source

    Source documentation

    Problem 10.3. To prove that there exists a positive real number~$c$ such that $\lVert e^n \rVert > e^{−cn}$, for every~$n \ge 1$. Posed by Mahler [Mah53].

    depends on sorry what this means

    Statement uses: Exists, Real, And, LT.lt, OfNat.ofNat, Nat, LE.le, Real.exp, HMul.hMul, Neg.neg, distToNearestInt

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    20 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem problem_10_3 :
        ∃ c : ℝ, 0 < c ∧ ∀ n : ℕ, 1 ≤ n → Real.exp (-c * n) < distToNearestInt (Real.exp n) := by
    …

    Mentions: c, distToNearestInt

  4. theorem Bugeaud01.waldschmidt Waldschmidt [Wal03] conjectured that a stronger result holds, namely that there exists a positive real number~$c$ such that $\lVert e^n \rVert > n^{-c}$ for every~$n \ge 2$ sorry line 84 source

    Source documentation

    Waldschmidt [Wal03] conjectured that a stronger result holds, namely that there exists a positive real number~$c$ such that $\lVert e^n \rVert > n^{-c}$ for every~$n \ge 2$. This is supported by metrical results [Kok45].

    Note: the bound $n^{-c}$ equals $1$ when $n = 1$ for all $c$, while the distance to the nearest integer is always at most $1/2$, so the conjecture must start at $n \ge 2$.

    depends on sorry what this means

    Statement uses: Exists, Real, And, LT.lt, OfNat.ofNat, Nat, LE.le, HPow.hPow, Neg.neg, distToNearestInt, Real.exp

    Proof uses: sorryAx, Lean.Name, Bool.false, Lean.Name.num, Lean.Name.str, Lean.Name.anonymous

    20 instances, coercions and auxiliary constants left out.

    Tactic trace: 1 steps

    Open to load the checked before-and-after goal states.

    theorem waldschmidt :
        ∃ c : ℝ, 0 < c ∧ ∀ n : ℕ, 2 ≤ n → (n : ℝ) ^ (-c) < distToNearestInt (Real.exp n) := by
    …

    Mentions: c, distToNearestInt

  5. theorem Bugeaud01.problem_10_3_of_waldschmidt Waldschmidt's conjecture is stronger than Mahler's: since $\log n \le n$ for $n \ge 1$, the polynomial lower bound $n^{-c}$ dominates the exponential lower bound $e^{-cn}$ line 95 source

    Source documentation

    Waldschmidt's conjecture is stronger than Mahler's: since $\log n \le n$ for $n \ge 1$, the polynomial lower bound $n^{-c}$ dominates the exponential lower bound $e^{-cn}$. For the $n = 1$ case (not covered by Waldschmidt's $n \ge 2$), we choose a larger constant using the numerical bound $\lVert e \rVert = 3 - e > 0$.

    standard axioms: Classical.choice, Quot.sound, propext what this means

    Statement uses: Exists, Real, And, LT.lt, OfNat.ofNat, Nat, LE.le, HPow.hPow, Neg.neg, distToNearestInt, Real.exp, HMul.hMul

    Proof uses: Eq.mpr, abs, HSub.hSub, id, Eq, congrArg, round, Eq.trans, Int, Real.round_exp_one_eq_three, Int.cast_ofNat, Ne, propext, abs_pos, Not.intro, Mathlib.Tactic.Linarith.lt_irrefl, Eq.mp, HAdd.hAdd, Mathlib.Tactic.Ring.of_eq, Mathlib.Tactic.Ring.Common.add_congr and 111 more

    160 instances, coercions and auxiliary constants left out.

    Tactic trace: 33 steps

    Open to load the checked before-and-after goal states.

    theorem problem_10_3_of_waldschmidt (h : type_of% waldschmidt) : type_of% problem_10_3 := by
    …

    Mentions: Bugeaud01.waldschmidt, Bugeaud01.problem_10_3